The invention relates to an image forming apparatus that includes: a plurality of image forming sections each for forming an image on a recording medium fed from a paper feeding section; and a plurality of paper output sections to which a recording medium bearing an image is to be selectively output.
There are two known methods for color image formation: the electrophotographic method and the inkjet method.
The electrophotographic method has the advantage of fast image formation and low running costs. This is because developer agent is heated and pressurized to be fused and firmly fixed to a recording medium and because the developer agent is comparatively inexpensive. However, this method has the disadvantage of poor color reproducibility. This is because of the developer agent, which is the mixture of thermoplastic resin with pigments or dyes. Poor transparency of the thermoplastic resin has a negative effect. Also, heat applied in a fusing process causes a change in color of pigments or dyes.
On the other hand, the inkjet method has the advantage of good color reproducibility. This is because this method uses ink with high transparency to form an image without applying heat. However, this method has the disadvantage of slow image formation and high running costs. This is because it takes long to dry ink and because the ink is comparatively expensive.
In most cases, partially color images of a single color or multiple colors, such as seals, illustrations, or graphs, inserted in part of textual images are formed on a recording medium, rather than full-color images.
In view of the foregoing, a combined image forming apparatus has been proposed that is provided with two types of image forming sections: an electrophotographic black-and-white image forming section and an inkjet color image forming section (see JP H08-183174A and JP 2002-192708A).
When the combined image forming apparatus is used to form a black-and-white image and a color image on a recording medium, there is definitely a noticeable difference in image quality between the black-and-white and color images as formed.
As a solution to the problem, electrophotographic black-and-white and color image forming sections can be provided for the purpose of forming a mixed image of black-and-white and color images without a noticeable difference in quality therebetween as well as enabling fast black-and-white image formation.
However, mere provision of the two types of electrophotographic image forming sections results in a complex transport route for recording medium, which makes it harder to remove a possible jam.
A feature of the invention is to offer an image forming apparatus that is smaller in size and has a reduced number of component elements and an enhanced operability, by provision of a single transport route along which a recording medium is transported, regardless of which one of a plurality of image forming sections forms an image on the recording medium,